Package org.apache.tomcat.util.digester

Class ArrayStack<E>

  • Type Parameters:
    E - Type of object in this stack
    All Implemented Interfaces:
    java.io.Serializable, java.lang.Cloneable, java.lang.Iterable<E>, java.util.Collection<E>, java.util.List<E>, java.util.RandomAccess
    public class ArrayStack<E>
extends java.util.ArrayList<E>

    Imported copy of the ArrayStack class from Commons Collections, which was the only direct dependency from Digester.

    WARNING - This class is public solely to allow it to be used from subpackages of org.apache.commons.digester. It should not be considered part of the public API of Commons Digester. If you want to use such a class yourself, you should use the one from Commons Collections directly.

    An implementation of the Stack API that is based on an ArrayList instead of a Vector, so it is not synchronized to protect against multi-threaded access. The implementation is therefore operates faster in environments where you do not need to worry about multiple thread contention.

    Unlike Stack, ArrayStack accepts null entries.

    Since:
    Digester 1.6 (from Commons Collections 1.0)
    See Also:
    Stack, Serialized Form

    • Field Summary

      • Fields inherited from class java.util.AbstractList

        modCount

    • Constructor Summary

      Constructors 
      Constructor Description
      ArrayStack()
      Constructs a new empty ArrayStack.
      ArrayStack​(int initialSize)
      Constructs a new empty ArrayStack with an initial size.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      boolean empty()
      Return true if this stack is currently empty.
      E peek()
      Returns the top item off of this stack without removing it.
      E peek​(int n)
      Returns the n'th item down (zero-relative) from the top of this stack without removing it.
      E pop()
      Pops the top item off of this stack and return it.
      E push​(E item)
      Pushes a new item onto the top of this stack.

      • Methods inherited from class java.util.ArrayList

        add, add, addAll, addAll, clear, clone, contains, ensureCapacity, equals, forEach, get, hashCode, indexOf, isEmpty, iterator, lastIndexOf, listIterator, listIterator, remove, remove, removeAll, removeIf, removeRange, replaceAll, retainAll, set, size, sort, spliterator, subList, toArray, toArray, trimToSize

      • Methods inherited from class java.util.AbstractCollection

        containsAll, toString

      • Methods inherited from class java.lang.Object

        finalize, getClass, notify, notifyAll, wait, wait, wait

      • Methods inherited from interface java.util.Collection

        parallelStream, stream, toArray

      • Methods inherited from interface java.util.List

        containsAll

    • Constructor Detail

      • ArrayStack

        public ArrayStack()
        Constructs a new empty ArrayStack. The initial size is controlled by ArrayList and is currently 10.

      • ArrayStack

        public ArrayStack​(int initialSize)
        Constructs a new empty ArrayStack with an initial size.
        Parameters:
        initialSize - the initial size to use
        Throws:
        java.lang.IllegalArgumentException - if the specified initial size is negative

    • Method Detail

      • empty

        public boolean empty()
        Return true if this stack is currently empty.

        This method exists for compatibility with java.util.Stack. New users of this class should use isEmpty instead.

        Returns:
        true if the stack is currently empty

      • peek

        public E peek()
       throws java.util.EmptyStackException
        Returns the top item off of this stack without removing it.
        Returns:
        the top item on the stack
        Throws:
        java.util.EmptyStackException - if the stack is empty

      • peek

        public E peek​(int n)
       throws java.util.EmptyStackException
        Returns the n'th item down (zero-relative) from the top of this stack without removing it.
        Parameters:
        n - the number of items down to go
        Returns:
        the n'th item on the stack, zero relative
        Throws:
        java.util.EmptyStackException - if there are not enough items on the stack to satisfy this request

      • pop

        public E pop()
      throws java.util.EmptyStackException
        Pops the top item off of this stack and return it.
        Returns:
        the top item on the stack
        Throws:
        java.util.EmptyStackException - if the stack is empty

      • push

        public E push​(E item)
        Pushes a new item onto the top of this stack. The pushed item is also returned. This is equivalent to calling add.
        Parameters:
        item - the item to be added
        Returns:
        the item just pushed